ENHANCING DELTA RESILIENCE Inauguration of Joost Stronkhorst as Lector in Building with Nature at Delta Academy, HZ University of Applied Sciences, 8 September 2016 CONTENTS

Welcome...... 3

Deltas & Resilience...... 4

Dynamics in deltas...... 4

Resilience of deltas...... 5

Sinking of deltas...... 5

Spatial layers of a delta...... 6

Building with Nature...... 8

Principles of Building with Nature...... 8

Sand nourishments to protect sandy coasts �������������������������������9

Building living breakwaters...... 10

Restoration of mudflats and salt marshes ���������������������������������11

Mangrove restoration...... 11

Managed realignment or ‘de-poldering’...... 12

Eco-friendly hard structures and dikes...... 13

Applied Research at Delta Academy...... 14

Living lab SW Delta...... 14

On our way to 2.0...... 14

Place for joint-fact-finding and co-creation ������������������������������15

Acknowledgements...... 17

References...... 18 WELCOME

Honourable Executive Board of HZ sustainable solutions to these complex University of Applied Sciences, dear problems. We try to achieve this through colleagues, students, family and friends, interdisciplinary education and applied research in the field of civil engineering, thank you for attending to my inauguration as aquatic eco-technology and delta Lector in Building with Nature at Delta management. Academy – Applied Research Centre (DA-ARC). In the next half an hour I will talk about delta The expanding populations and economy in resilience and ways to enhance resilience low-lying deltas are facing the same using Building with Nature solutions. I will give challenges: flood risks, environmental a short introduction on deltas, define delta degradation, loss of natural capital and a lack resilience, go over different Building with of resilience towards and Nature concepts, showcase some of the work subsidence. The mission of Delta Academy that the research group Building with Nature is is to educate the next generation of doing here in the Dutch SW delta and present professionals which is capable of creating new ideas for future work, here and abroad.

I build upon the work by Mindert de Vries, my appreciated predecessor and colleague at Deltares in Delft who did pioneering work and launched many Building with Nature projects in this region. Along with my fellow lector Professor Tjeerd Bouma, I have the pleasure of working with a wonderful team of dedicated researchers, a team capable of good science, teaching, tough fieldwork and teamwork. Our challenge is to understand how Building with Nature can enhance delta resilience to improve the level of flood safety and for the sake of natural capital and delta development at large.

Joost Stronkhorst

3 DELTAS & RESILIENCE

DYNAMICS IN DELTAS Mississippi delta. The Nile delta is an example of Maybe you recognise this iconic photograph a wave-dominated delta, resulting in a more even taken from the moon by the crew of Apollo 8 on distribution of river sediment along the coastline. Christmas day 1968. It is entitled ‘Earth Rise’. At If tides are dominant, it results in a shape like, that time, it made mankind more aware that the for instance, the Ganges-Brahmaputra delta. blue planet we live on is precious and that we should treat our living environment with care. All kinds of dynamic geophysical processes are taking place: morphological changes, inundation For 4.5 billion years the earth and the moon have of the tidal flats, nutrient cycles, salinity formed a couple. The gravitational effect of the gradients, etc. These processes influence the moon is responsible for the tides on earth, one of ecology and results in high biodiversity in and the dynamic factors in deltas. The tidal cycle of productivity of the water, on land and the flood and ebb pushes seawater in and out of an wetlands in between. estuary, twice daily, every day of the year.

Deltas are formed where rivers supply abundant amounts of sediments into the sea. The shape of a delta mainly depends on three sediment transport processes: the flow of the river water, the powerful forces of waves and the tidal currents. According to the Galloway classification (Galloway, 1975) river-dominated deltas develop in front of very large rivers that enter a calm sea with minimal waves and tides: for example, the Earth rise

4 Enhancing Delta Resilience Man has become a serious factor in shaping vegetation growth, accretion etc.; deltas too, as we can see in the Dutch SW Delta. • Estuarine waterways are deepened in such a This delta of the rivers , and way that if dredging stops the natural has a sandy coast along the , conditions of the estuary return immediately, islands with fertile but low-lying polders and including the network of tidal channels and a estuaries with tidal flats and channels. Over the good ecological status; last century we have changed the delta • Human communities living in deltas are aware dramatically by shortening the delta coastline of disaster risks and climate change and have and embanking and compartmentalising the self-organising coping capabilities; branches. The most influenced are the stagnant • Aquaculture in delta areas take place within lakes (-Zoommeer and both the ecosystem’s carrying capacity; freshwater, and Veere both salt • Industries and cities on the delta are water). The least modified areas are the tide- independent of freshwater supply from dominant Scheldt estuary and Oosterschelde outside their region in times of drought, by tidal bay, but even here the human impact on the protecting and re-using their freshwater estuary development is very significant. resources most effectively.

RESILIENCE OF DELTAS Resilience can evolve through cycles of growth, Resilience can be defined as the ability of a accumulation, crisis and renewal and often self- system to withstand and recover from hazards organises into unexpected new configurations. (e.g. flooding). The term has been used since the This way a delta can absorb stress and bounce 1990s in Dutch water policy plans (Ministry of back from a setback without suffering damage. Transport & Public Works, 1999), by the World Wildlife Fund in their vision on delta SINKING OF DELTAS development (WWF, 2008). More recent it is Ladies and gentlemen, many urbanized deltas used by, for example, the United Nations and are sinking (Syvitski et al., 2009). This is a result World Bank in the context of disaster risk of different factors including: i) subsidence, a reduction (UNISDR, 2015), the City of New York drop in surface level due to natural compaction as their vision behind restoring the damage of sediments or accelerated by extraction of caused by hurricane Sandy (NYC, 2013) and by groundwater, oil, or gas or draining of land; ii) research networks devoted to the governance low sediment input because sediments are and capacity building of communities (Post being trapped upstream behind hydroelectric Carbon Institute, 2013). or sediment transport is interruption by coastal structures and iii) sea level rise. Let’s Delta resilience in my view can be understood as zoom in on the last topic. the amount of change each part of a delta can undergo while retaining essentially the same The effect of sea level rise on deltas is function and structure as well as the degree to illustrated by the paleogeographic which each part of a delta is capable of self- reconstruction of the Dutch SW delta made by organisation and adaptation to the change. De Vos (2015). The reconstruction covers the In practice this means, for instance, that: last 11,000 years (Holocene). In the first part of • Flood defences are designed to dissipate the Holocene, sea level rose rapidly and the storm and wave energy that may hit a coastline retreated because the supply of coastline, with natural foreshores that rebuild sediment was smaller than the demand for and adapt themselves through sedimentation, sediment to grow apace with rising sea level.

5 When sea level rise started to slow down, the sediment supply exceeded the sediment demand, and the shoreline moved seaward. Later on and protected by sandy coastal barriers marshland started to develop in the freshwater environment. Some 2500 year ago the sand barriers were breached and seawater flooded the area again. During the last thousand years, inhabitants of the Dutch SW Delta have reshaped the area by impoldering large parts of the delta for agriculture and protecting themselves from the sea by raising dikes, with the Delta works as the final masterpiece.

Here in Flushing, at the mouth of the Scheldt estuary, sea level has been recorded since 1862. The sea level is rising by an average of 2 mm per year (equal to 0.2 m in a century). But over the last few decades, the rise has accelerated to 3 mm per year. This is an effect of global warming as addressed by the International Panel on Climate Change (IPCC, 2014). However, high-end We will have to find holistic solutions that scenarios predict up to 1.8 m of sea level rise by simultaneously ensure flood safety, productivity the end of this century if CO2 emissions continue and biodiversity. Given the complexity of our unabated (Jevrejeva et al., 2014). This may delta systems this will be extremely difficult. We actually happen, considering the alarming rapid need delta programmes to make it happen. melting of Antarctic ice sheets reported in Nature this summer (DeConto & Pollard, 2016)! SPATIAL LAYERS OF A DELTA A very useful way to analyse delta resilience is Faster sea level rise, faster subsidence and low by imagining a delta as a three-layer model sediment inputs reduce delta resilience and consisting of a base, a network jeopardise delta life for coming generations. So: and an occupation layer “it is the sediment, stupid!” (Bucx et al., 2014).

6 Enhancing Delta Resilience The base layer is the bio-geophysical layout of a developed the CHW App at Deltares and received delta: geology, morphology, hydrology, ecology the HZ Stern Award for best BSc thesis of 2016. etc. The network layer encompasses the man-made infrastructure of dikes, waterways, A well know Dutch example of the consequences ports and roads. The base layer sets the of lack of resilience is the 1953 . The boundary conditions for the network layer and poor condition of the sea defences (network together they enable the occupation layer, which layer) caused the disaster that hit the SW delta. encompasses the built-up environment, The Delta Works were the firm and robust economic activities and so forth. Changes in the response to this great disaster; it took 40 years base layer usually take place at larger scales of to complete (1958-1997). time and space (e.g. sea level rise and subsidence) than in the other two layers. Today the Dutch delta is indeed a wealthy place and regarded as the safest delta in the world. The bio-geophysical factors of the base layer That doesn’t mean that the job is done; the sea determine coastal hazards like, for instance, level is rising and sea defences need to be erosion or salt water intrusion or flooding. We maintained. Can we equip ourselves to be recently developed an internet application that resilient, bounce back and adapt to the allows the identification of erosion hazards at any turbulence ahead? According to the UN one of given coast in the world (http://chw.openearth. the essentials for making urbanized deltas eu/viewer). The application uses global open resilient is protecting ecosystems and making access data of physical factors and the or restoring other natural buffers for mitigating classification method called Coastal Hazard floods, storm surges, or other natural hazards. Wheel (Rosendahl Appelquist L, Halsnæs K, 2015). Delta Academy student Alex Levering

7 BUILDING WITH NATURE

PRINCIPLES OF BUILDING 1. restoration of natural sediment transport WITH NATURE 2. re-use of dredged material Using natural materials and the constructive 3. sand nourishment forces of nature to build and maintain flood 4. mangrove and saltmarsh restoration defences or rehabilitate degraded ecosystems is 5. re-shaping cliffs referred to as Building with Nature (Waterman, 6. development of living breakwaters 2011; Borsje et al., 2012; Temmerman et al., (mussel, oyster and coral reefs) 2013; De Vriend et al, 2015). The idea is to make 7. smart use of hard structures nature-based flood defences by using wind, 8. small-scale protection measures waves, tides and currents, to use the stabilising 9. managed realignment and spatial planning effect of mussel and oyster beds or the (Stronkhorst et al., 2013). wave-damping effect of mangrove forests and salt marshes, and to use sand, silt and clay as Building with Nature solutions typically fulfil building material. A suite of eco-engineering multiple functions besides the primary function options are available, including: they are designed for. For example, wetlands protect against floods but also function as

nurseries for commercial fish species, as CO2

8 Enhancing Delta Resilience sinks, as aesthetical landscape elements, or as Preservation of the Coastline' programme (Hillen tourist attractions. Building with Nature aims to & Roelse, 1995). This is an excellent example of balance traditional natural values with Building with Nature. The long-term goal is to functionality and economic benefits. allow the coast to grow apace with rising sea level and combat coastal erosion. Large dredging In the , Building with Nature is vessels collect sand from the deeper North Sea supported by the water sector through the and place it on the foreshore or beach, from public–private consortium Ecoshape and where tides and waves redistribute it naturally government institutions involved in coastal and wind brings the sand into the dunes. For the infrastructure and ecosystem development (van sand nourishments along the coast of Slobbe et al., 2013). Building with Nature has I estimated that the benefits exceed the costs already been applied in many hydraulic because the sand nourishments save expensive engineering projects, for example, the Dutch sea defence re-enforcements on the landside; ‘Room for the River’ project, the Sigma plan for provide favourable conditions for beach the Scheldt river in , the Dutch ‘Coastal recreation and tourism; create extra dune habitat weak links’ project, Flemish Bays, the program and protect the fresh groundwater reserves in the engineering-with-nature of the US Army Corps dunes. From the perspective of asset of Engineers and the Dutch programme management, the Dynamic Preservation of the 'Dynamic Preservation of the Coastline'. Coastline programme is an economically sensible approach. Similar Building with Nature strategies SAND NOURISHMENTS TO are needed for many other delta coasts as well as PROTECT SANDY COASTS for other basins in the SW Delta. When in 1990 a storm hit the dunes here close by on the island of Walcheren, the resilience of this The sand volume of the dunes is a good indicator coast was tested to the limit. Fortunately, of resilience. To cope with the high-end sea level Walcheren was not inundated, though the sand rise scenario mentioned earlier I believe that for buffer was greatly reduced. The 1990 storm had at least the coming century we can create an impact at a national level and initiated the sand enough resilience to the Dutch coasts by nourishment schemes that Rijkswaterstaat has applying sand nourishments. This is because we been implementing ever since, the 'Dynamic are very lucky in having vast reserves of sand in

9 the North Sea (Stronkhorst et al., in prep). At a protect the sand flats. Rijkswaterstaat and NGO global level, however, sand is becoming a rare Natuurmonumenten have commissioned our natural resource used above all for the research group and our research partners construction of roads and buildings (see UNEP Deltares, Imares and NIOZ to make a sand publication Sand, rarer than one thinks (Peduzzi nourishment design for the sand flat Roggenplaat et al. 2014). So many sandy coastlines will that enables wading birds to visit the area for at retreat or require very large investments in hard least the next 25 years. So together with coastal engineering measures to prevent that Rijkswaterstaat we are working on sustainable from happening. solutions for this type of coastal erosion (van de Werf et al., 2016). In the winter of 2018/19 a I began my career as an environmental dredging company will execute the sand researcher in the Delta Department (Deltadienst) nourishment of 1.3 million cubic meters of sand. in Middelburg during the construction of the Our research consortium will monitor the Delta Works. In 1986 the Oosterschelde storm developments that follow. surge barrier was finished and is operational ever since. At that time we investigated the BUILDING LIVING ecological effects of, among others, a temporal BREAKWATERS closure of the storm surge barrier. Today we are Reefs of oysters and mussels may have more concerned about its long-term side effect sediment stabilisation and erosion prevention on the sand balance of the Oosterschelde. This is capabilities. This is being tested in combination because the barrier is limiting the sand transport with a sand nourishment at the Oesterdam, to the sand flats while the waves continue to Oosterschelde (Salvador de Paiva et al., 2016; erode the sand flats, depositing sand in the deep Van den Brink, 2016). Building with Nature tidal channel. For wading birds these sand flats researchers and many students are working are crucial feeding grounds. Therefor sand hard to collect and analyse data. The research nourishments have been executed at Galgeplaat consortium with Deltares, Imares and NIOZ will and Oesterdam (Boersema et al., 2016a) to soon present its final findings and answer the

10 Enhancing Delta Resilience importantly, have a great capacity to store the greenhouse gas carbon dioxide in soil and biomass for centuries.

Beneficial use of dredged material may include the creation of wetlands in the Scheldt estuary to compensate the loss of salt marshes in the SW delta (Storm, 1999). A very large volume of approximately 10 million cubic meters of sediment is being dredged every year to maintain the estuarine waterway to . I hope we can find partners to start a Living Lab question on the morphological effectiveness on the development of more wetlands, for and ecological benefits of the sand nourishment instance, along the south shore of Zuid- and added value of the oyster reefs. Beveland. This fits nicely in the research agenda Our group and partners are trying to build a of the Flemish Dutch Scheldt Commission durable littoral mussel bed in the Oosterschelde (VNSC) that is coordinating the trans-boundary and develop a maintenance strategy for it. The management of the Scheldt estuary. aim is to achieve a number of seemingly conflicting goals, such as: create new, cost- This year lector Tjeerd Bouma, an effective production locations for the shellfish internationally renowned scientist on the industry; develop nature-friendly methods to ecology of mud coasts, will start a new Building protect erosion of intertidal areas and increase with Nature project on the Dutch south border of the natural value of tidal wetlands in the context the Scheldt estuary. Here new groynes are of the Natura 2000 objectives. Many partners being built by the water board; the research is share a great interest in this research and many and commissioned by the Province of . students are and will be involved in this four- The question is if these hard structures will year project. enhance deposition of sand and mud from the Scheldt estuary and result in durable intertidal RESTORATION OF MUDFLATS flats. Colleague Carla Pesch is working on a AND SALT MARSHES comparable issue in the Port of . Crucial for delta resilience is the presence of wetlands, including mud flats, salt marshes and Lector Robert Trouwborst is currently working mangrove forests. In the last century half of on a research proposal to apply new sensor these habitats on earth were lost due to all technology to improve our monitoring capability kinds of coastal developments: land to quantify the content of mud in the water and to reclamation, building of aquaculture ponds, link this to many practical questions related to erosion, etc. Mud is an essential substrate for mussel culturing, the design of a dike toe and salt marshes and mangrove forests. Wetland water quality in, for instance, the port of vegetation provides accelerated soil building Rotterdam together with Hogeschool Rotterdam. with sea level rise (Kirwan et al., 2016) and protects coastlines from incoming waves. MANGROVE RESTORATION Additionally, wetlands are nurseries for fish To better understand the conditions in Asia with regulate nutrient levels in the water and, very regard to ‘Enhancing delta resilience’ the Delta

11 Academy has selected the coastal city of international water ambition, which is to test Surabaya as a research area because of the delta solutions together with foreign parties and added value to our research agenda and educate young professionals (http://www. reciprocity in the relationship with the Technical waterinternationaal.nl/). University of Surabaya (ITS). Surabaya will provide a living lab on topics like, for example: MANAGED REALIGNMENT OR mangrove restoration (taking place near ‘DE-POLDERING’ Wonorejo), sustainable port development (taking Beaches and wetlands in front of a sea defence place in Teluk Lamong) and post-disaster that are eroding eventually disappear because management (for the Lumpur Lapindo case). they cannot move landward due to the very The Delta Academy has already established a presence of the sea wall or dike. This is called good network for collaboration with ITS, NUFFIC coastal squeeze. If space is available in the and the Indonesian Netherlands Association and hinterland a new inland sea defence can replace partners Witteveen+Bos and Deltares. Our the one close to the coastline. This ‘managed research group will focus on the mangrove realignment’ creates accommodation space for restoration, using to our advantage recent BSc sediments to settle and form tidal flats and salt theses of Delta Academy students and the marshes. It is a way of increasing resilience in experiences of our partners with mangrove an estuarine and coastal zone. This approach is restoration at the central north coast of Java frequently used in the UK, and some other (Demak). This approach is in line with the Dutch European counties, however, in the SW Delta it

12 Enhancing Delta Resilience has been applied only a few times on a small scale because of public concern about 'de-poldering’ (Stronkhorst & Mulder, 2014). Our research group, students, colleagues of Deltares, IMARES and NIOZ are working on this issue at Perkpolder (Scheldt estuary). The managed realignment at Perkpolder took place in 2015 and transformed 75 ha of farmland into a low-dynamic muddy habitat as nature compensation for the deepening of the shipping lane to Antwerp. Measurements show rapid deposition of mud and a fast colonisation by small macro benthos and wading birds (Boersema et al, 2016b). Salt is by Deltares and companies produced building materials with has been halted by an ingenious smart drainage uneven surface that may attract more flora and system. Similar developments are taking place small fauna. The new materials are being tested in: Rammegors, Hedwig polder, Zwin, by our team on dikes of the regional water board Waterdunen and Haringvliet and are mainly (waterschap Scheldestromen). Examples of triggered by nature restoration. These projects substrates are: concrete blocks with holes; may contribute to delta resilience, but there is mastic asphalt mixed with lava stones or oyster no concerted research agenda to learn from shells (Van Oijen, 2016). Students are involved in these cases for future projects. the intensive monitoring. Final results will be published early 2017. ECO-FRIENDLY HARD STRUCTURES AND DIKES We expect to continue this type of research for Dikes protect polders from flooding. The dikes two reasons: to come up with nature-based dike along the Oosterschelde require special re-enforcement methods in the Oosterschelde attention since this is a National Park and to meet Natura 2000 regulations; and to Natura 2000 area. Here, dike re-enforcements enhance biodiversity on other hard substrate require eco-friendly dike building material. In a surfaces like wind turbine platforms in the project called Building-for-Nature various North Sea etc.

13 APPLIED RESEARCH LIVING LAB SW AT DELTA ACADEMY DELTA ON OUR WAY TO DELTA WORKS 2.0

What can society in the SW delta expect of Building with Nature in the long-term? Two interesting scenarios have been sketched by Wiersma et al (2011). The first scenario shows much wetland and natural estuarine gradients. The second scenario shows a dune massif that connects the islands protecting Over the year a very large number of students the delta while valuable freshwater from the have been involved in our work and improved rivers are and stored in the Grevelingen and their research skills. On Delta Academy Oosterschelde. Maybe these are ways of website students can find portfolio of research enhancing delta resilience. But how will we assignments, including lector assignments, achieve this, is there a grand design for Delta stages, minors, and thesis topics. Works version 2.0?

The Applied Research Centre covers four It appears that step-by-step we are on our topics: Building with Nature, Aquaculture in way to a Delta Works 2.0! An inventory of Delta Areas, Water Technology and Resilient on-going Building with Nature related Deltas. We have a highly qualified staff (~20 projects in the SW delta shows that already FTEs) that combines research and teaching. more than 60 real-life cases are in progress Our research projects are funded by or are planned (reference year 2015). Most companies, the Centre of Expertise Delta projects contribute to delta resilience and Technology and funds for applied research serve flood safety and nature development at provided by the Netherlands Organisation the same time. You can read all about it in for Scientific Research/NWO. the book The New Delta by Bianca de Vlieger and TU Delft professors Joost Schrijnen and This summer, an independent audit Han Meyer (for sale in October of this year). committee reviewed our achievements. There is great appreciation of our scientific impact, So there is a wealth of real-life cases that how we contribute to the innovation of provide opportunities for learning-on-the-job. professional practice in the region, of our It’s high time to declare the SW delta as living contribution to the renewal of the curriculum lab for enhancing delta resilience! and our function as a regional research hub. Following the audit we have come to the PLACE FOR JOINT-FACT- conclusion that delta resilience is an FINDING AND CO-CREATION overarching theme in our work. This will be A living lab in my view is cooperation between made more explicit in our new strategic universities, industry, governments and research agenda 2017-2020 we are working civil society for open innovation (scientific, on right now. social and technological) to solve a concrete

14 Enhancing Delta Resilience practical problem in a given region through co-creation. A living lab is also a showcase for a particular solution and a platform for joint-fact-finding.

Many research opportunities lie ahead. To mention a few: funding possibilities by the Centre of Expertise Delta Technology, Netherlands Organisation for Scientific Research, the national Delta Technology Knowledge and Innovation Agenda 2016-2019 of Top sector Water and the national Water and Climate Knowledge and Innovation Programme (NKWK), the national Science Delta Resilience that includes new Building Agenda, the EU Horizon 2020 programme with with Nature topics related to, for instance: Societal Challenge #5 on ‘nature-based solutions’. In addition, there are several A. Smart use of dredged material to create interesting new initiatives that are expanding new wetlands in the Scheldt estuary, the research opportunities even further, B. Coastal developments and sand including Delta Platform, Centre of Expertise nourishment along the Dutch delta coast, on Wind and Sea and the development of a MSc C. Building-for-nature on hard substrates in in Delta Development at Delta Academy. the SW Delta region, D. Business-innovation-through-nature To change these opportunities into new in ports, concrete innovation projects Delta Academy E. Managed realignment in the SW Delta, will continue and expand the collaboration F. and last but not least mangrove restoration with companies, governmental organisations, for a resilient coast of Surabaya NGOs, consulting firms, other higher education and research institutes. Together we can establish a Living Lab Enhancing

15 ACKNOWLEDGEMENTS

I thank Willem den Ouden, Dean of Delta Academy and Adri de Buck, Chairman of the Executive Board HZ University of Applied Sciences for their confidence in me. I express my gratitude to my fellow lectors and researchers for their enthusiasm and above all the Building with Nature group that consists of Anneke van den Brink, PhD candidate Jildou Schotanus, Carla Pesch, Samara Hutting, Edwin Paree, Matthijs Boersema, Joao Salvador de Silva, Tjark van den Heuvel, Tim van Oijen and Tjeerd Bouma. I very much appreciate the efforts of Liliane Geerlings and Marlies van Eenennaam in the Living Lab Surabaya. Marijke van de Voorde and Evy van der Wees, thank you for helping to organise this happening.

A special thanks goes to my wife Sonja for her support all the way.

16 Enhancing Delta Resilience REFERENCES

• Boersema M, Bouma T, Ysebaert T, van den • IPCC, 2014. Coastal systems and low-lying Brink A, van der Werf J, 2016a. areas. Eds Wong PP et al. Chapter 5 in Fifth Effectiveness of local sand nourishment at Assessment Report (AR5), pp. 361-409. the Oesterdam for safety and ecosystem Cambridge University Press, Cambridge, preservation. Poster presentation at the United Kingdom and New York, NY, USA. conference Adaptation Futures, Rotterdam, • Jevrejeva S, Grinsted A & Moore JC, 2014. 10-13 May 2016. Upper limit for sea level projections by • Boersema M, van der Werf J, Bouma J & 2100. Environmental Research Letters, Stronkhorst J, 2016b. Morphological 9(10), 104008. developement of the Perkpolder basin. • Kirwan ML, Temmerman S, Skeehan EE, Poster presentation at ECSA, conference on Guntenspergen GR & Fagherazzi S, 2016. estuarine restoration, Antwerp, 5-9 July Overestimation of marsh vulnerability to 2016. sea level rise. Nature Climate Change 6, • Borsje BW, van Wesenbeeck BK, Dekker F, 253–260. Paalvast P, Bouma TJ, van Katwijk MM, de • NYC, 2013. A stronger, more resilient New Vries MB, 2011. How ecological engineering York. City of New York. can serve in coastal protection. Ecological • Ministry of Transport & Public Works, 1999. Engineering 37 (2), 113-122. Fourth national policy document on water • Bucx T, et al., 2014. Comparative management in the Netherlands. assessment of the vulnerability and • Peduzzi et al. 2014. Sand, rarer than one resilience of deltas. Delta Alliance report#7. thinks. UNEP Global Environmental Alert Delta Alliance International, Delft- Service (GEAS), March 2014.http://www. Wageningen, The Netherlands. unep.org/pdf/UNEP_GEAS_March_2014.pdf • DeConto RM & Pollard D, 2016. Contribution • Post Carbon Institute, 2013. Resilient of Antarctica to past and future sea-level against what? rise. Nature 531, 591–597. • Rosendahl Appelquist L, Halsnæs K, 2015. • De Vos P, 2015. Origin of the Dutch Coastal The Coastal Hazard Wheel system for landscape. PhD thesis, University of Utrecht. coastal multi-hazardassessment & • De Vriend HJ, van Koningsveld M, management in a changing climate. Journal Aarninkhof SGJ, de Vries MB, Baptist MJ, of Coastal Conservation 19, 2, 157-179. 2015. Sustainable hydraulic engineering • Salvador de Paiva J, Walles B, Ysebaert T & through Building with Nature. J of Hydro- Bouma T, 2016. Using pacific oyster environment Research 9:159 - 171. Crassostrea gigas for sediment stabilization: • Galloway, W. E. (1975) Process framework how their effectiveness depends on biological for describing the morphologic and and environmental setting. Presentation at stratigraphic evolution of deltaic depositional ECSA, conference on estuarine restoration, systems. In: Models for Exploration, Houston Antwerp, 5-9 July 2016. Geological Society, 87-98. • Storm, K, 1999. Slinkend Onland. • Hillen R & Roelse P, 1995. Dynamic Rijkswaterstaat, Middelburg, report preservation of the coastline in the AX-99.007 [in Dutch] Netherlands. Journal of Coastal • Stronkhorst J, van der Spek A, van Maren B, Conservation, 1, pp. 17-28. 2013. A quick scan of Building-with-Nature

17 solutions to mitigate coastal erosion in • Van der Werf J, Boersema M, Nolte A, Colombia. Commissioned by Ministry of the Schrijvershof R, Stronkhorst J, de Vet L, Environment, Colombia, Report 1207028, Walles B & YsebaertT, 2016. Variantenstudie Deltares, Delft, The Netherlands Roggenplaat suppletie. Centre of Expertise • Stronkhorst J, 2013. Economic rationale of Delta Technology (Deltares, Delta Academy, sand nourishments along the North Sea Imares, NIOZ), commissioned by coast of the island of Walcheren, Report Rijkswaterstaat. 1207778, Deltares, Delft. • Van Oijen T, Salvador de Paiva J, van Heuvel • Stronkhorst J & Mulder J, 2014. T, Boersema M, Bouma T, 2016. Building for Considerations on managed realignment in Nature: Adjusting the surface structure of the Netherlands, In: Esteves, LS (Ed). concrete revetments to stimulate Managed realignment: A viable long-term biodiversity in the intertidal zone. Poster coastal management strategy? Springer presentation at the conference Littoral Briefs in Environmental Science. New York: Biarritz, 25-29 October 2016. Springer. • Van Slobbe E, de Vriend HJ, Aarninkhof S, • Stronkhorst J, de Ronde J, Coastline Lulofs K, de Vries M, Dircke P, 2013. management and flood safety - part Building with Nature: in search of resilient • Stronkhorst J, Giardino A, Huisman B, storm surge protection strategies. Nat Santos FD, in prep. Long term sand Hazards 65:947–966. nourishment strategies to mitigate • Waterman, RE, 2011. Integrated Coastal shoreline retreat at the low-lying coasts of Policy via Building with Nature. ISBN/EAN Holland (The Netherlands) and Aveiro 978-90-805222-3-7. (Portugal). • Wiersma A, Tangelde M, Brouwer J, Abma, • Temmerman S, Meire P, Bouma TJ, Herman R, 2011. Sustainable scenarios for the PMJ, Ysebaert T & de Vriend HJ, 2013. Southwest Delta based on Building with Ecosystem-based coastal defence in the Nature strategies. Deltares, Utrecht report face of global change. Nature 504 (7478), 1202061-000. 79-83. • WWF, 2008. High tide for Low Netherlands • UNISDR, 2015. Sendai Framework for [in Dutch]. Disaster Risk Reduction 2015-2030. • Van den Brink, A, 2016. Biodiversity on Artificial Oyster Reefs. Poster presentation at ECSA, conference on estuarine restoration, Antwerp, 5-9 July 2016.

Published by: HZ University of Applied Sciences Photographers: Edwin Paree, Tjark van den Heuvel, Joop van Houdt, Rijkswaterstaat Contact Address: [email protected]

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